Investigation of Surface Settlement and Wall Deflection Caused by Braced Excavation in Spatially Variable Clays Based on Anisotropic Random Fields

This research aims to assess the influences of the spatial variability of soil parameters on the ground surface and retaining wall deformation induced by braced excavation. A series of anisotropic random fields are generated and used for the finite difference analysis in this paper. A procedure for automating the Monte Carlo simulation is employed to ascertain the influences of coefficient of variation and scale of fluctuation ( SOF ) of soil stiffness parameters on the excavation-induced responses. In addition, the effects of horizontal SOF and vertical SOF are distinguished in the anisotropic framework. The stochastic results indicate that the presented computational framework is effective in the investigation of excavation-induced deformations. Further probabilistic analyses are performed to evaluate the failure probabilities of surface settlement (SS) and retaining wall deflection (RWD). This study shows the importance of addressing the spatial variability of stiffness parameters for soil and structure problems. A series of modes for SS and RWD are presented with consideration of the effects of weak stiffness regions. The effects of vertical SOF on excavation-induced deformations are larger than those of horizontal SOF . The concept of vertical SOF correlation is proposed to explain that the most scattered result occurs when the vertical SOF is close to the size of the excavation. The research can provide a beneficial reference for advance warning of failure or hazard when performing probabilistic assessment of excavation-induced deformations.